ADAPTABLE SWING ASSEMBLY FOR CHAIR BACK TILT, CHAIR BACK TILT LOCKING MECHANISM AND CHASSIS

Abstract

The present invention provides an adaptive swing component for chair back reclining, a chair back reclining locking mechanism and a chassis, wherein the adaptive swing component comprises a main shaft and a motion assembly, wherein the motion assembly comprises a first moving member, a track seat and a second moving member which rotate synchronously around the main shaft; the chair back reclining locking mechanism comprises the above-mentioned adaptive swing component, which has an adjustment state and a locking state, wherein in the adjustment state, the first moving member is disengaged from the second moving member, the chair back can rotate and drive the first moving member to move in the adjustment direction and rotate relative to the main shaft; and the locking mechanism is applied to the chassis; in the locking state, the first moving member is combined and locked with the second moving member to lock the current reclining angle of the chair back; the entire motion assembly is interlocked and rotates together relative to the main shaft to realize adaptive swinging and prevent motion interference and jamming; the structural locking can solve the problems of friction plate wear and failure, noise, etc., and the operation is easier, the structure is simple, and the cost is maintained at a low level.

Claims

1. An adaptive swing assembly for chair back reclining, comprising: a main shaft and a motion assembly, wherein: the motion assembly is rotatably arranged on the main shaft and swings on the main shaft; the motion assembly comprises a track seat and a first moving member and a second moving member arranged on the track seat, the track seat comprises a first sliding track and a second sliding track that are perpendicular to each other, the first moving member and the second moving member slide in the first sliding track and the second sliding track, respectively; the first moving member and the first sliding track are attached to the first moving member and can rotate synchronously with the track seat relative to the main shaft; the second moving member and the second sliding track are attached to the second moving member and can rotate synchronously with the track seat relative to the main shaft; the first moving member or the second moving member is sleeved on the main shaft and is rotatably connected to the main shaft.

2. The adaptive swing assembly according to claim 1, wherein: the track seat is slotted through to form a first sliding track, the first moving member has a first limiting surface and a second limiting surface, the first limiting surface is in contact with an upper groove wall of the first sliding track, and the second limiting surface is in contact with a lower groove wall of the first sliding track.

3. The adaptive swing assembly according to claim 2, wherein: the main shaft is arranged along a left and right direction, the second sliding track is arranged along the left and right direction, the second moving member is sleeved on the main shaft, the track seat is sleeved on the second moving member and the second moving member is slidably arranged in the second sliding track.

4. A chair back reclining locking mechanism comprising: an adaptive swinging assembly according to claim 1; an adjustment direction and a locking direction, wherein the adjustment direction coincides with the first sliding track, and the locking direction coincides with the second sliding track, the first moving member moves in the adjustment direction as the chair back rotates, the second moving member moves in the locking direction, and locks the first moving member when the second moving member approaches the first moving member or unlocks the first moving member when the second moving member leaves the first moving member; an adjustment state and a locking state, wherein in the adjustment state, the first moving member is disengaged from the second moving member, the chair back rotates and drives the first moving member to move in the adjustment direction and rotates relative to the main axis; in the locking state, the first moving member and the second moving member are combined and locked to lock a current reclining angle of the chair back.

5. The chair back reclining locking mechanism according to claim 4, wherein: in the adjustment state, when the chair back rotates, the adjustment direction tilts with the swing of the motion assembly.

6. The chair back reclining locking mechanism according to claim 4, wherein an axial direction of the main shaft coincides with the locking direction, and the second moving member is sleeved on the main shaft and slidably cooperates with the main shaft in the second sliding track.

7. The chair back reclining locking mechanism according to claim 6, wherein the main shaft is a metal part.

8. The chair back reclining locking mechanism according to claim 7, wherein: the second moving member is a metal part, the second moving member comprises a locking part and a sliding part, the sliding part is arranged in the second sliding track and fits with the second sliding track, and the locking part is configured to lock with the first moving member when the locking part is close to the first moving member; the locking part and the sliding part are integrally formed.

9. The chair back reclining locking mechanism according to claim 7, wherein: the second moving member comprises a locking part and a sliding part, the sliding part is arranged in the second sliding track and fits with the second sliding track, and the locking part is configured to lock with the first moving member when the locking part is close to the first moving member; the locking part and the sliding part are spliced together, and the locking part is a metal part, and the sliding part is a plastic part.

10. The chair back reclining locking mechanism according to claim 4, wherein: the first moving member is provided with a receiving groove in the locking direction, and the receiving groove extends along a length direction of the first moving member; an inner tooth portion is provided in the receiving groove, and an outer tooth portion is provided on the second moving member; in the locked state, the first moving member enters the receiving groove and the first moving member and the second moving member are locked by meshing the inner tooth portion with the outer tooth portion.

11. The chair back reclining locking mechanism according to claim 4, wherein the track seat is composed of two left-right symmetrical track parts.

12. A chassis comprising: a base, a chair back connecting member and the chair back reclining locking mechanism as described in claim 4, wherein the chair back reclining locking mechanism is rotatably arranged on the base, the main shaft is arranged on the base along left and right directions, a linkage member is provided between the chair back reclining locking mechanism and the chair back connecting member, and the linkage member is configured so that when the chair back connecting member rotates relative to the base, the motion assembly rotates on the main shaft; when the chair back reclining locking mechanism is in the adjustment state, the chair back connecting member can rotate relative to the base; when the chair back reclining locking mechanism is in the locked state, the chair back reclining locking mechanism locks the rotation between the chair back connecting member and the base, and makes the chair back connecting member stay in the rotated position.

13. The chassis according to claim 12, wherein the base has a mounting groove, the mounting groove opens upward, and the chair back reclining locking mechanism is arranged in the mounting groove.

14. The chassis according to claim 12, further comprising an operating rod, which is inserted into the base along the left-right direction, and a transmission member being provided between the operating rod and the second moving member; wherein the operating rod is configured to pull the operating rod to drive the transmission member to move, and the transmission member drives the second moving member to slide in the second sliding track, and switches the chair back reclining locking mechanism between the adjustment state and the locking state.

15. The chassis according to claim 14, wherein: the transmission member is a torsion spring, which is rotatably arranged on the base, and two ends of the torsion spring are respectively connected to the operating rod and the second moving member.

16. The chassis according to claim 15, wherein: an avoidance groove extending along the locking direction is provided on the track seat outside the second moving member, and a slot is provided on the second moving member, and a torsion spring arm at one end of the torsion spring is inserted into the slot through the avoidance groove; the avoidance groove is configured so that when the operating rod is pulled, the torsion spring drives the second moving member to move in the second sliding track, and the avoidance groove avoids the movement of the torsion spring arm.

17. The chassis according to claim 12, wherein: the linkage member is a connecting pin, the connecting pin is inserted into the first moving member and the chair back connecting member, the first moving member and the chair back connecting member are rotatably connected through the connecting pin.

18. The chassis according to claim 12, wherein: the linkage member comprises a seat connector, a connecting pin and a rotating sliding shaft, the seat connector is rotatably arranged on the base, the connecting pin penetrates through the seat connector and the first moving member, the first moving member and the seat connector are rotatably connected through the connecting pin; the rotating sliding shaft is arranged on the seat connector, a sliding groove is provided on the chair back connecting member, the rotating sliding shaft is inserted in the sliding groove, the rotating sliding shaft and the sliding groove are configured to link the chair back connecting member with the seat connector, and when the chair back connecting member rotates relative to the base, the seat connector is driven to rotate relative to the base.

19. The chassis according to claim 12, wherein: the chair back reclining locking mechanism is vertically arranged in the chassis, and the first moving member is vertical and inclined in a front-to-back direction; when the chair back connecting member rotates backward, the first moving member drives the track seat to swing and slide downward in the track seat.

20. The chassis according to claim 19, wherein the base comprises a downwardly convex extension seat, the main shaft is arranged on the extension seat, and the track seat is arranged in the extension seat.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a schematic diagram of a three-dimensional structure of the chassis in Example 1 of the present invention;

[0019] FIG. 2 is a second schematic diagram of the three-dimensional structure of the chassis in Example 1 of the present invention;

[0020] FIG. 3 is a schematic diagram of the three-dimensional structure of the swing assembly in Example 1 of the present invention;

[0021] FIG. 4 is a cross-sectional view of the swing assembly in Example 1 of the present invention;

[0022] FIG. 5 is a schematic diagram of the three-dimensional structure of the swing assembly in Example 1 of the present invention when it is in a locked state;

[0023] FIG. 6 is a schematic diagram of the three-dimensional structure of the swing assembly in Example 1 of the present invention when it is in an adjustment state;

[0024] FIG. 7 is a side view of the locking mechanism when the chair back connecting member is not tilted in Embodiment 1 of the present invention;

[0025] FIG. 8 is a side view of the locking mechanism of the chair back connecting member after reclining in Example 1 of the present invention;

[0026] FIG. 9 is a schematic diagram of the three-dimensional structure of the track seat in Example 1 of the present invention;

[0027] FIG. 10 is a schematic diagram of the three-dimensional structure of the track portion in Example 1 of the present invention;

[0028] FIG. 11 is a cross-sectional view of the rail seat in Example 1 of the present invention;

[0029] FIG. 12 is a schematic diagram of the three-dimensional structure of the second moving member in Example 1 of the present invention;

[0030] FIG. 13 is a schematic diagram of the three-dimensional structure of the first moving member in Example 1 of the present invention;

[0031] FIG. 14 is an exploded view of the swing assembly in Example 1 of the present invention;

[0032] FIG. 15 is a schematic diagram of the three-dimensional structure of the chassis in Example 3 of the present invention;

[0033] FIG. 16 is a second schematic diagram of the three-dimensional structure of the chassis in Example 3 of the present invention;

[0034] FIG. 17 is a schematic diagram of the internal structure of the chassis in Example 3 of the present invention.

[0035] The reference numerals of the drawings are: main shaft 1; track seat 2; track portion 20; main body part 201; clamping part 202; first groove 203; second groove 204; third groove 205; first moving member 3; first limiting surface 31; second limiting surface 32; second moving member 4; locking part 41; sliding part 42; first sliding track 5; second sliding track 6; base 7; chair back connecting member 8; connecting pin 9; mounting groove 10; elastic buckle 11; clamping hole 12; accommodating groove 13; inner tooth portion 14; outer tooth portion 15; operating rod 16; torsion spring 17; avoidance groove 18; slot 19; seat connector 21; rotating sliding shaft 22; sliding groove 23; extension seat 24. [0036] 1-3, 5, 6, 12, 14

DETAILED DESCRIPTION OF THE INVENTION

[0037] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0039] In the description of the present invention, the terms first, second, third, etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0040] The specific implementation methods of the present invention are as follows: [0041] Embodiment 1: As shown in FIGS. 3-8 and 14, the present invention provides an adaptive swinging assembly for chair back tilting, comprising a main shaft 1 and a motion assembly, wherein the motion assembly is rotatably arranged on the main shaft 1 and swings on the main shaft 1; the motion assembly comprises a track seat 2 and a first moving member 3 and a second moving member 4 arranged on the track seat 2, the track seat 2 comprises a first sliding track 5 and a second sliding track 6 which are perpendicular to each other, the first moving member 3 and the second moving member 4 slide in the first sliding track 5 and the second sliding track 6 respectively; the first moving member 3 and the first sliding track 5 are attached to the first moving member 3 so as to be able to rotate synchronously with the track seat 2 relative to the main shaft 1; the second moving member 4 and the second sliding track 6 are attached to the second moving member 4 so as to be able to rotate synchronously with the track seat 2 relative to the main shaft 1; the first moving member 3 or the second moving member 4 is sleeved on the main shaft 1 and is rotatably connected with the main shaft 1.

[0042] Since the motion assembly is integrally rotatably arranged on the main shaft 1, and the first moving member 3 and the second moving member 4 are both matched with the track seat 2 to rotate synchronously relative to the main shaft 1, when any one of the first moving member 3 or the second moving member 4, in addition to sliding, also rotates relative to the main shaft 1, it will drive the track seat 2 to rotate synchronously, and at the same time drive the other of the first moving member 3 or the second moving member 4 to rotate synchronously. The entire motion assembly is interlocked and rotates together relative to the main shaft 1 to achieve adaptive swing, thereby preventing motion interference and jamming.

[0043] As shown in FIGS. 1 and 2, the above-mentioned adaptive swinging assembly for the reclining of the chair back is applied to a chair back reclining locking mechanism, which is applied to a chassis, which comprises a base 7 configured as a main body support, a chair back reclining locking mechanism, and a chair back connecting member 8 connected to the first moving member 3; the main shaft 1 is arranged on the base 7 along the left-right direction, the chair back connecting member 8 is rotatably connected to the rear end of the base 7, and a linkage member is provided between the chair back reclining locking mechanism and the chair back connecting member 8, and the linkage member is configured so that when the chair back connecting member 8 rotates relative to the base 7, the motion assembly rotates on the main shaft 1. In this embodiment, the linkage member is a connecting pin 9. The front end of the chair back connecting member 8 is rotatably connected to the rear end of the first moving member 3 through a connecting pin 9. The connecting pin 9 is inserted into the rear end of the first moving member 3 and the front end of the chair back connecting member 8. The chair back connecting member 8 is configured to connect the chair back; when the chair back reclining locking mechanism is in an adjustment state, the chair back connecting member can rotate relative to the base; when the chair back reclining locking mechanism is in a locked state, the chair back reclining locking mechanism locks the rotation between the chair back connecting member and the base, and makes the chair back connecting member stay in the rotated position.

[0044] As shown in FIGS. 5-8, the chair back reclining locking mechanism has an adjustment direction and a locking direction. The adjustment direction coincides with the first sliding track 5, and the locking direction coincides with the second sliding track 6. The first moving member 3 moves in the adjustment direction as the chair back rotates, and the second moving member 4 moves in the locking direction, and locks the first moving member 3 when the second moving member 4 approaches the first moving member 3 or unlocks the first moving member 3 when the second moving member 4 leaves the first moving member 3; it also has an adjustment state and a locking state. In the adjustment state, the first moving member 3 and the second moving member 4 are disengaged, and the chair back can rotate and drive the first moving member 3 to move in the adjustment direction and rotate relative to the main shaft 1; in the locking state, the first moving member 3 and the second moving member 4 are combined and locked to lock the current reclining angle of the chair back.

[0045] The locking of the friction plate in the prior art is replaced by the locking of the mechanism, thereby solving the problems of failure and noise caused by wear. In addition, the operation is easier, the structure is simple, and the cost is maintained at a low level.

[0046] Specifically, as shown in FIGS. 1, 2, 9 and 10, the base 7 opens upwardly to form a mounting groove 10 for accommodating the motion assembly. The main shaft 1 is arranged on the base 7 along the left-right direction and then crosses the mounting groove 10. The track seat 2, the first moving member 3 and the second moving member 4 are all located in the mounting groove 10. The track seat 2 is composed of two left-right symmetrical track portions 20. The track portion 20 comprises a main body part 201 and a clamping part 202. The clamping part 202 protrudes from the main body part 201 from top to bottom. The track seat 2 is composed of two left-right symmetrical track portions 20. The track portion 20 comprises a main body part 201 and a clamping part 202. The clamping part 202 protrudes from the main body part 201 from top to bottom. When located in the mounting groove 10, the main body part 201 is closer to the base 7 relative to the clamping part 202, and the clamping part 202 is closer to the center of the base 7.

[0047] When the two track portions 20 are assembled, the two clamping parts 202 are pressed against each other; the clamping parts 202 are recessed toward the opposite surfaces to form a first groove 203, and the first groove 203 extends along the front and rear directions. After the two track portions 20 are assembled, the two first grooves 203 together form the first sliding track 5; therefore, the track seat 2 is grooved or slotted through the front and rear to form the first sliding track 5.

[0048] As shown in FIGS. 10-12 and 14, a second groove 204 and a third groove 205 are provided on the main body part 201 along the left-right direction. The third groove 205 is closer to the clamping part 202 than the second groove 204. The second sliding track 6 is the second groove 204. The second moving member 4 comprises a locking part 41 and a sliding part 42. The sliding part 42 is arranged in the second groove 204. The shape of the second groove 204 is configured so that the sliding part 42 fits with the second groove 204, that is, the edge of the sliding part 42 fits with the second sliding track 6. The locking part 41 is arranged in the third groove 205, and the shape of the third groove 205 is adapted to the locking part 41, so that the locking part 41 can completely enter the third groove 205; the locking part 41 is used to lock with the first moving member 3 when approaching the first moving member 3; the locking part 41 and the sliding part 42 are spliced together, and the two are connected by the elastic buckle 11 and the clamping hole 12. The locking part 41 is a metal plate with a clamping hole 12, and the sliding part 42 is an injection-molded plastic part, and the elastic buckle 11 is molded on the sliding part 42. The locking part 41 is the main force-bearing part, and the sliding part 42 plays a more guiding role and cooperates with the track seat 2. Therefore, the locking part 41 can be a metal part, which can reduce costs. At the same time, the locking part 41 and the sliding part 42 are relatively simple to assemble, which is conducive to production and will not lead to a decrease in production efficiency. In addition, the main shaft 1 and the first moving member 3 are also the main force-bearing parts, so they are also metal parts; the force on the chair back will be transmitted to the main shaft 1 through the first moving member 3 and the second moving member 4. The first moving member 3 and the main shaft 1 are metal parts that can ensure strength and supporting capacity, so that the locking mechanism has a long service life and is not easy to be damaged.

[0049] Further, as shown in FIGS. 3, 4 and 13, the first moving member 3 has a first limiting surface 31 and a second limiting surface 32, the first limiting surface 31 is in contact with the upper groove wall of the first sliding rail 5, and the second limiting surface 32 is in contact with the lower groove wall of the first sliding rail 5; the limiting of the track seat 2 and the first moving member 3 is achieved by the first limiting surface 31 and the second limiting surface 32 of the first moving member 3 being in contact with the upper groove wall and the lower groove wall of the first sliding rail 5, the first moving member 3 can only slide relative to the track seat 2, and when the first moving member 3 rotates, the track seat 2 will rotate with it.

[0050] Similarly, the sliding part 42 in the second moving member 4 fits with the second sliding track 6. When the track seat 2 rotates, it will drive the second moving member 4 to rotate around the main shaft 1; the main shaft 1 is arranged along the left and right directions, the second sliding track 6 is arranged along the left and right directions, the second moving member 4 is sleeved on the main shaft 1, the track seat 2 is sleeved on the second moving member 4 and the second moving member 4 is slidably arranged in the second sliding track 6; therefore, there is a rotation limit between the second moving member 4 and the track seat 2. When the first moving member 3 moves, it drives the track seat 2 to rotate, and the second moving member 4 also rotates with the track seat 2. The first moving member 3, the second moving member 4 and the track seat 2 all rotate synchronously with the main shaft 1.

[0051] To sum up, the first moving member 3 mainly moves in the front-to-back direction, but when the chair back is tilted and the chair back connecting member 8 rotates, the first moving member 3 will also produce a certain amount of rotation. When the first moving member 3 rotates, it will drive the track seat 2 to rotate, and the track seat 2 will drive the second moving member 4 to rotate on the main shaft 1; since the second moving member 4 is rotatably arranged on the main shaft 1, the second moving member 4 rotates synchronously with the track seat 2, and the track seat 2 rotates synchronously with the first moving member 3, so the rotation of the first moving member 3 is also around the main shaft 1, so there is only one rotation point of the motion assembly, which is the main shaft 1, and the motion assembly as a whole can rotate around the main shaft 1, so that when the chair back is tilted and adjusted, the motion assembly can adaptively tilt and rotate, so that the tilting movement of the chair back and the movement of the locking mechanism will not interfere, and the locking of the chair back after tilting can be smoothly achieved.

[0052] Furthermore, in terms of direction, the axial direction of the main shaft 1 coincides with the locking direction, and the second moving member 4 is sleeved on the main shaft 1 and slides with the main shaft 1 in the second sliding track 6; the second moving member 4 moves in the locking direction, and since the second moving member 4 is slidably arranged on the main shaft 1, after the first moving member 3 moves, the second moving member 4 moves along the axial direction of the main shaft 1 and connects with the first moving member 3 to achieve the tilt locking of the chair back and keep it in the current position. Therefore, the locking direction is the left-right direction, while the adjustment direction is roughly the front-back direction, and in the adjustment state, when the chair back rotates, the adjustment direction tilts with the swing of the motion assembly; when the chair back rotates and drives the first moving member 3 to move, the first moving member 3 will rotate due to the rotation of the chair back in addition to displacement, and when the first moving member 3 rotates, it will drive the entire motion assembly to rotate on the main shaft 1. The mechanism has a strong adaptive ability, so that the tilt locking after the chair back rotates can be smoothly achieved; the tilt of the adjustment direction is also a manifestation of adaptive ability.

[0053] The combination and locking of the first moving member 3 and the second moving member 4 are as follows:

[0054] As shown in FIGS. 5, 6, 12 and 13, the first moving member 3 is a long plate-shaped metal part; the first moving member 3 is provided with a receiving groove 13 in the locking direction, and the receiving groove 13 extends along the length direction of the first moving member 3; an inner tooth portion 14 is provided in the receiving groove 13, and an outer tooth portion 15 is provided on the locking part 41 of the second moving member 4. In the locked state, the locking part 41 of the first moving member 3 enters the receiving groove 13 and the first moving member 3 and the second moving member 4 are meshed and locked by the inner tooth portion 14 and the outer tooth portion 15; in the adjustment state, the locking part 41 leaves the receiving groove 13 and enters the third groove 205, the first moving member 3 and the second moving member 4 are disengaged, and the first moving member 3 can move in the first sliding track 5 as the chair back rotates. The length direction of the first moving member 3 is the adjustment direction. When the first moving member 3 moves in the adjustment direction, the position of the second moving member 4 corresponding to the accommodating groove 13 will also change. When the second moving member 4 is at different positions of the accommodating groove 13 and the inner tooth portion 14 is engaged with the outer tooth portion 15, the chair back is locked at different reclining positions and the chair back maintains the reclining angle at this time.

[0055] The force on the chair back is transmitted to the first moving member 3 through the chair back connecting member 8 and the connecting pin 9. The first moving member 3 further transmits the force to the locking part 41 through the meshing of the inner tooth part 14 and the outer tooth part 15. The locking part 41 is directly arranged on the main shaft 1, so it transmits the force to the main shaft 1. The main shaft I finally transmits the force to the base 7. In order to ensure the strength and sufficient load-bearing capacity, the base 7, the main shaft 1, the locking part 41 and the first moving member 3 are all metal parts with higher strength.

[0056] The density of the inner tooth portion 14 is greater than 55/100 mm. Fine and dense teeth realize stepless adjustment. The inner tooth portion 14 is provided on the upper and lower groove walls of the accommodating groove 13, and correspondingly, the upper and lower surfaces of the locking part 41 are also provided with outer tooth portions 15. In this embodiment, the inner tooth portion 14 is 74 mm long and has 42 teeth. [0057] Embodiment 2: The difference between this embodiment and embodiment 1 is that the locking part 41 and the sliding part 42 of the second moving member 4 are both metal members. The details are as follows:

[0058] The second moving member 4 is a metal part, and the second moving member 4 comprises a locking part 41 and a sliding part 42. The sliding part 42 is arranged in the second sliding track 6 and fits with the second sliding track 6. The locking part 41 is used to lock with the first moving member 3 when it is close to the first moving member 3; the locking part 41 and the sliding part 42 are integrally formed; the second moving member 4 is a force-bearing part, and is made of metal to increase strength; the locking part 41 and the sliding part 42 can be integrally formed, which is more convenient to manufacture.

[0059] The chassis also comprises an operating rod 16, which is inserted on the base 7 along the left-right direction, and a transmission member is provided between the operating rod 16 and the second moving member 4. The operating rod 16 is configured to pull the operating rod 16 to drive the transmission member to move, and the transmission member drives the second moving member 4 to slide in the second sliding track 6, and switches the chair back reclining locking mechanism between the adjustment state and the locking state; the transmission member is a torsion spring 17, which is rotatably arranged on the base 7, and the two ends of the torsion spring 17 are respectively connected to the operating rod 16 and the second moving member 4; an avoidance groove 18 extending along the locking direction is provided on the track seat 2 outside the second moving member 4, and a slot 19 is provided on the second moving member 4, and a spring arm at one end of the torsion spring 17 is inserted in the slot 19 through the avoidance groove 18; the avoidance groove 18 is configured so that when the operating rod 16 is pulled, the torsion spring drives the second moving member 4 to move in the second sliding track 6, and the avoidance groove 18 avoids the movement of the spring arm.

[0060] The locking and unlocking switching in the locking mechanism can be achieved by pulling the operating rod 16 left and right. Not only is the operation easy and simple, but the user can also reach it with just a hand, which is more convenient. The transmission member is preferably a torsion spring 17, which is not only low in cost, but also has a simpler structure for the mounting seat of the torsion spring 17 in the chassis. The torsion spring 17 as a transmission member also has a buffering effect during locking: when the first moving member 3 and the second moving member 4 are locked, the inner tooth portion 14 and the outer tooth portion 15 are not fully aligned and engaged, but not only can the pulling operation still be performed, but the pulling operation will not be more laborious, and after the chair back is slightly tilted, the second moving member 4 can be automatically locked into the first moving member 3, that is, the inner tooth portion 14 and the outer tooth portion 15 can be delayed in engagement without affecting the operation. [0061] Embodiment 3: The chair back reclining locking mechanism is applied to another chassis, specifically:

[0062] As shown in FIGS. 15-17, in this embodiment, the chassis has a seat-back linkage function; the linkage member comprises a seat connector 21, a connecting pin 9 and a rotating sliding shaft 22. The seat connector 21 is rotatably arranged on the base 7. The connecting pin 9 is penetrated through the seat connector 21 and the first moving member 3. The first moving member 3 is rotatably connected to the seat connector 21 through the connecting pin 9; the rotating sliding shaft 22 is arranged on the seat connector 21, and a sliding groove 23 is provided on the chair back connecting member 8. The rotating sliding shaft 22 is inserted into the sliding groove 23. The rotating sliding shaft 22 and the sliding groove 23 are configured to link the chair back connecting member 8 with the seat connector 21. When the chair back connecting member 8 rotates relative to the base 7, it drives the seat connector 21 to rotate relative to the base 7; the chassis in this scheme can realize the linkage of the chair back, and drive the seat to rotate relative to the base 7 while the chair back is tilted, thereby reducing the feeling of rubbing the back and improving comfort.

[0063] The chair back reclining locking mechanism is vertically arranged in the chassis, and the first moving member 3 is vertical and inclined in the front-to-back direction; when the chair back connecting member 8 rotates backward, the first moving member 3 drives the track seat 2 to swing and slide downward in the track seat 2. Specifically, the base 7 comprises a downwardly convex extension seat 24, the main shaft 1 is arranged on the extension seat 24, and the track seat 2 is arranged in the extension seat 24. The extension seat 24 comprises at least two plates, and the two plates are arranged at intervals along the left and right to install the main shaft 1 and accommodate the track seat 2; the extension seat 24 can be integrally formed with the base 7, or can be fixedly connected to the base 7 by welding; the extension seat 24 is used to increase the volume of the base 7 in the up-and-down direction, so that the vertically arranged locking mechanism can be smoothly installed on the base 7; in this chair back linkage chassis, the volume of the base 7, that is, the internal space of the chassis is small, and the thickness of the base 7 is also small, which makes it difficult to accommodate the above-mentioned locking mechanism. Therefore, for this chassis that is not easy to accommodate, the locking mechanism originally arranged in the front-to-back direction can be changed to be arranged in the up-and-down direction, which can also achieve the reclining locking of the chair back.

[0064] In this embodiment, although the orientation of the chair back reclining locking mechanism is changed, the control of the second moving member 4 by the operating rod 16 through the torsion spring 17 can still be achieved as long as the bending of the torsion spring 17 is adaptively changed.